pass check_ip and proxies to GetIp constructor

The `GetIp` class doesn't need to keep a reference to the middleware, so
there is no reason to pass the middleware instance to the `GetIp` class

actionpack/lib/action_dispatch/middleware/remote_ip.rb

@@ -74,7 +74,7 @@ def initialize(app, check_ip_spoofing = true, custom_proxies = nil)
     # requests. For those requests that do need to know the IP, the
     # GetIp#calculate_ip method will calculate the memoized client IP address.
     def call(env)
-      env["action_dispatch.remote_ip"] = GetIp.new(env, self)
+      env["action_dispatch.remote_ip"] = GetIp.new(env, check_ip, proxies)
       @app.call(env)
     end
 
@@ -82,10 +82,10 @@ def call(env)
     # into an actual IP address. If the ActionDispatch::Request#remote_ip method
     # is called, this class will calculate the value and then memoize it.
     class GetIp
-      def initialize(env, middleware)
+      def initialize(env, check_ip, proxies)
         @env      = env
-        @check_ip = middleware.check_ip
-        @proxies  = middleware.proxies
+        @check_ip = check_ip
+        @proxies  = proxies
       end
 
       # Sort through the various IP address headers, looking for the IP most